Thought I'd share a workaround in Coremetrics for viewing channels in the Session Funnel Report.
Since I can trend full metrics in the Top Line Summary with a segment on them, I trended Tracked Sessions, Tracked Product Page Views, Carts Initiated, and Ordered Shopping Carts.
I didn’t have a pure number for “Sessions that view a Product Page,” which would be the second step in the cart. BUT since I had total sessions and total product page views, I took the Page Views/Session # per week and multiplied it by the weekly Total Sessions to get an estimated number of Sessions with a Product View.
Curious, intrawebs, does that seem credible to you?
I then did a % of total Sessions for each cart step that followed (using the Carts initiated and Ordered Carts metrics).
Gave me a rough views of metrics. Your mileage may vary!